Maternal iodine supplements in areas of deficiency

Abstract

Background: Iodine deficiency is the leading preventable cause of intellectual impairment in the world. Although iodine supplementation is generally considered to be safe, there is a possibility of high doses of iodine suppressing maternal thyroid function.

Objectives: The objective of this review was to assess the effects of iodine supplementation before or during pregnancy in areas of iodine deficiency.

Search strategy: We searched the Cochrane Pregnancy and Childbirth Group trials register.

Selection criteria: All acceptably controlled trials of maternal iodine supplementation during pregnancy with clinical outcomes.

Data collection and analysis: Eligibility and trial quality were assessed by two reviewers.

Main results: Three trials involving 1551 women were included. In two trials, iodine supplementation was associated with a statistically significant reduction in deaths during infancy and early childhood (relative risk 0.71, 95% confidence interval 0. 56 to 0.90). Iodine supplementation was associated with decreased prevalence of endemic cretinism at the age of four years (relative risk 0.27, 95% confidence interval 0.12 to 0.60) and better psychomotor development scores between four to 25 months of age.

Reviewer's conclusions: Iodine supplementation in a population with high levels of endemic cretinism results in an important reduction in the incidence of the condition with no apparent adverse effects.